Hmmm..., I suppose for the fuel tank (kerosene), there's no reason I couldn't get away with a fiberglass tank instead of the aluminum. How did you keep the piston straight as it went down? Was there a rod end coming out of the top or just a thick piston?
-Bob On 11/18/2013 02:40 PM, qbert@xxxxxxxxxxxxxxx wrote:
Our 6" Condor tank was nearly the same except the actual tank was fiberglass and nearly 8 ft long and the bottom had a shallow cone to drain all the peroxide out. We also used a aluminium band on the oust side to give the screws something to hold on to other than fiberglass. We also used a thin PTFE layer against the fiberglass for safety and a piston to make sure all the peroxide went out the bottom. I got the idea of the design and piston from the Hybrid guys. No need for anti-slosh baffles. We had our in-flight tanks tested to 600psi and one tested to destruction at about 1050psiRobert At 12:21 PM 11/18/2013, you wrote:Nice write-up. I haven't found it necessary to use anti-slosh baffles on the rockets I've flown with 7 and 8" diameter tanks. Anyone else have any experience that differs?--- Carl On 11/17/2013 8:15 PM, Robert Watzlavick wrote:I completed hydro-testing today on a prototype tank based on the design I mentioned a few weeks ago.In summary, no leakage or damage was observed after 2 cycles to 750 psi. There looks to be a small amount of permanent deformation in the center of the bulkheads (~0.005 inches) but nothing to worry about. While assembling the parts, as the o-ring slid past the tank wall holes, it shredded some small pieces off. I didn't debur the inside hole edge as well as I could have so I'll clean them up a bit and see if it helps.Discussion is at: http://www.watzlavick.com/robert/rocket/ photos are at: http://www.watzlavick.com/robert/rocket/rocket1/photos/index.html -Bob-- Carl Tedesco Flometrics, Inc. 5900 Sea Lion Place, Suite 150 Carlsbad, CA 92010 tel: 760-476-2770 ext. 515 fax: 760-476-2763 ctedesco@xxxxxxxxxxxxxx www.flometrics.com